US worldwide travel warning
Armed police are seen outside the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia. The U.S. State Department issued a rare worldwide travel warning to U.S. citizens Friday, in the wake of the Sydney siege. Getty Images

The U.S. government issued a rare worldwide travel alert for its citizens Friday, citing the attack this week against civilians in Sydney, Australia, and saying that the country's interests overseas could be targeted over the upcoming holiday period.

“An analysis of past attacks and threat reporting strongly suggests a focus by terrorists not only on the targeting of U.S. government facilities but also on hotels, shopping areas, places of worship, and schools, among other targets, during or coinciding with this holiday period,” the U.S. State Department said in the warning.

The alert will remain in place until Mar. 19, 2015, and urges U.S. citizens to “remain alert to local conditions and for signs of danger.”

Referring to the attack in Sydney, Australia, earlier this week, which resulted in the deaths of two civilians taken hostage by a gunman in a cafe in Australia's largest city, the warning urged U.S. citizens to “be extra cautious, maintain a very high level of vigilance.”

State Department and intelligence officials said that there is no specific threat to Americans traveling abroad, but they are concerned that Monday's violence could inspire copycat attacks, according to a report from NBC News.

The U.S. State Department issues worldwide travel alerts sparingly. Friday's alert is the first such warning that the department issued throughout the whole of 2014, though scores of warnings have been issued for specific countries.

The last time the U.S. issued a worldwide travel alert was in August 2013, in response to threats from al Qaeda, according to Buzzfeed.

For more information on what State Department travel alerts mean for everyday travelers, click here.